Defination of Atmosphere

In scientific terms that atmosphere is defined as layered system of gases that surround any specific body which is a material body of a specific mass and weight. The which surround the specific mass of body are in fact attracted by the overall gravity of the body and thus are retained and never lost by the body. To retain these gases for a longer period of time, the gravity is required to be high and the atmospheric temperature is required to be low. Only in such a condition the gases will stick to the body and will not go away.

Atmospheric pressure is defined as the overall force per unit area that the surrounding gases apply on the body due to their presense around the body. Our earth also has the atmosphere of its own in which we all live and spend the whole of our lives. The atmosphere of the earth is filled with lots of gases that fill the whole atmosphere of the earth.